In the past there have been many proposals for the provision of spring loaded arms for mounting a mud-flap on a truck or the like. While such structures have in general been quite useful for logging trucks, in highway situations there have been some disadvantages associated with the general prior art structures. Such prior art structures, as exemplified by U.S. Pat. Nos. 2,652,266 and 2,801,867, have provided for up-and-down movement of the mud-flap in addition to pivotal movement about a vertical axis. When mud or the like builds up on the mud-flaps, however, they have a tendency to droop due to the ability to move up and down, and therefore they do not maintain a constant vertical relationship with respect to the wheel. Also, there is a tendency in such prior art structures for the flaps to bounce and shake when the vehicle to which they are attached goes over small bumps in the road, which bouncing and shaking under some circumstances can have an effect on the life of the flaps. U.S. Pat. No. 4,007,944 shows a prior structure apparently moveable about a vertical axis only, but requiring two separate return springs.
According to the present invention a mud-flap supporting assembly is provided for mounting a mud-flap on the vehicle which is eminently suited for use in highway situations. According to the present invention the assembly comprises a horizontally disposed mounting arm adapted to have a mud-flap attached thereto, and means for mounting the mounting arm to a vehicle at an attachment point including means for substantially preventing movement of the arm in a vertical direction, and means for allowing pivotal movement of the arm about a vertical axis adjacent the operative attachment point of the arm to the vehicle. The means for allowing pivotal movement of the arm about a vertical axis includes a vertical pin, an arm portion for receiving the pin, and a support portion adapted to be connected to the vehicle for receipt of said pin, the pin passing through the arm portion and the support portion. Additionally, spring means operatively connected between the arm and arm portion for centering the arm are provided, so that the arm is normally in the first position but may pivot against the spring bias about the vertical axis out of the first position, and so that it will be automatically returned by the spring biasing means to the first position. The means for preventing movement of the arm in a vertical direction may comprise interfering portions of the arm portion and the support portion, and the spring means preferably comprises a single coil spring having hook-shaped end portions, or a single compression coil spring.
The three preferred assemblies according to the present invention may be removed without a hammer or other special tools, and the springs associated therewith may be readily replaced. According to the first and third embodiments of the invention, the means for preventing vertical movement of the arm also comprises means for mounting the arm and arm portion for horizontal telescopic movement with respect to each other against the bias of the spring means. Stop means are provided for preventing complete separation of the arm from the arm portion should the spring means break, and the arm portion preferably includes a yoke having a pair of arms and a cross portion.
In the first embodiment, the cross portion of the yoke has a slot formed therein for passage of a portion of the spring means into the area between the yoke arms, and the yoke arms have vertically aligned bores for receipt of the vertical pin. The means for allowing pivotal movement of the arm about the vertical axis further comprises a terminating portions of the arm biased into engagement with a portion of the support portion by the spring biasing means, the arm terminating portion comprising a top plate portion that covers the vertical pin in the first position of the arm, but which does not cover the vertical pin when the arm is pivoted away from the first position, a pair of bores being provided in the top plate in the arm portion for receipt of a blocking member to hold the arm against the bias of the spring means in a position to which it has been moved wherein the top plate does not cover the vertical pin.
In the third embodiment, the arm portion comprises first and second arm portions, the first arm portion being rigidly attached to the arm and providing a yoke, and the second arm portion being a cross member that is guided by and slidable with respect to the first arm portion. The second arm portion includes an end plate with a guide rod extending therefrom, and a bushing is provided operatively attached to the first arm portion and arm, the bushing receiving the guide rod. A single coil compression spring is disposed between the end plate and the bushing.
According to a second embodiment of the invention, the means for allowing pivotal movement of the arm about a vertical axis further includes the arm portion formed as a yoke having a pair of yoke arms, at least one lever member pivotally connected to the yoke arms at an intermediate portion of the lever member, and the lever member having one free end thereof in operative engagement with the support portion, and having the other free end thereof retaining the spring means while being slidable with respect to the spring means; the arm and arm portion being rigidly attached together. Access may readily be gained to the spring hooked end portion between the yoke arms for ready removal and insertion of the spring.
It is a primary object of the present invention to provide a simple mud-flap supporting assembly especially suitable for highway vehicles. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.